Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It discloses the pay-per-call cost ($0.01 USDC), which is useful, but doesn't state whether the call is read-only, whether it reverts for non-contract addresses, or what the response format looks like. The cost disclosure is a positive, but the behavioral profile is incomplete.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single sentence that front-loads the core purpose and includes the cost detail. It is efficient, though the cost detail could arguably be placed in annotations or a separate field.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter tool with no output schema, the description covers the core purpose and cost, but lacks behavioral details like response format, error behavior, and whether the ERC-20 metadata is returned for all addresses or only contracts. It is adequate but has clear gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single parameter 'address' is described as 'polygon address (0x...)' in the schema. The description adds the context that the address is checked for contract status, but doesn't add format details beyond the schema. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Whether a polygon address is a contract') and resource ('polygon address'), and adds bytecode size + ERC-20 metadata. It clearly distinguishes from siblings like polygon_balance and polygon_token, though it doesn't explicitly name them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for checking if an address is a contract and retrieving metadata, but provides no explicit when-to-use guidance or exclusions. It doesn't mention alternatives like polygon_token for ERC-20 metadata, leaving the agent to infer the tool's niche.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.